How Are Diamonds Measured?

When you are choosing a diamond for a ring, a necklace, or any other setting, you have a lot of options. Being able to design your own ring or to buy your diamonds directly from a supplier gives you a wide range of choices to pick from. You can choose from many different cuts, weights, styles, clarities, and so on.

It can, however, all feel fairly overwhelming for someone who is not an experienced diamond buyer. There are a lot of terms that are not used in any context other than the context of diamonds and there are also many terms that are used differently when in the context of diamonds. Here are some of them.

Carats

Carats are a measurement of weight; they should not be confused with “karats” which are a measurement of the purity of gold. A carat is the standard unit of weight for a diamond and is equivalent to 200g. It comes from the Arabic name for the Carob tree. The nuts of the tree were originally used as a point of reference for the weight of different precious metals and stones.

Because of the fairly standard weight of diamond as a mineral, most diamonds that are a certain carat weight are also about the same size. The density of the diamond also affects how large it is. For example, a one carat diamond is about six millimetres in diameter. A two carat diamond, however, is a little over eight millimetres in diameter. It’s not twice the size of the former.

When first pulled from the ground, a diamond is typically a rough mineral that is largely formless. It is then cut down to its purest essence. That clears away many of the different mineral deposits that have built up around the diamond. Clearing all of that away gives the diamond the best possible clarity and uniformity of shape. To do that, however, a jeweller has to make several decisions. The decisions the jeweller makes have become known as the diamond’s cut.

Each smooth face of the diamond is called a facet. A diamond is often measured by the number of facets in the cut, but it can also be measured by the shape of the facets. Since diamonds are transparent, they can act as prisms. White light is made up of every colour of light. It then passes into the diamond, where the many different facets break it into multiple bands of coloured light. Thus, when it passes out, it is many different colours. That is the prism effect.

You need to make sure you do as much research as possible into the diamond you choose. A diamond is ideally cut to maximise its prism effect. Different facets and different cuts are somewhat limited by the diamond itself. Certain cuts require a diamond of a certain size and a certain clarity, but some cuts are actually proprietary, and you can only get them from certain vendors.